The study establishes the experimental basis for the assignment of Danish grown Sitka spruce to the European strength class system as defined in EN 338 (1995). Seven hundred and ten boards representative of normal Danish commodity are visually strength graded according to the Nordic rules (INSTA 142, 1996) and subsequently taken to failure in either bending or tension. The results show that Danish grown Sitka spruce of grades "T1" and "T2 and better" easily satisfy the requirements for the strength classes C18 and C24 levels, respectively. Danish grown Sitka spruce therefore meets the requirements at the same level as Danish grown Norway spruce. The study shows that Sitka spruce and Norway spruce of the same origin exhibit highly comparable mechanical properties. Key words: annual ring width, bending strength, characteristic strength, dry density, EN 338, INSTA 142, modulus of elasticity, Sitka spruce, strength class, strength grading, tensile strength.
|Journal||Scandinavian Journal of Forestry Research|
|Publication status||Published - 2000|